The bds suspension website says that you can`t properly lift the front of a truck 2" with a single spacer because it will make the ball joint the droop limit and this will cause premature wear or failure. BDS makes a strut spacer that fits within the limits of the factory ball joint angles and adds the additional lift from a strut pre load spacer. The extra preload puts more pressure on the tire/wheel combination to keep it in contact with the road.
Is there any truth to this or are they just blowing smoke? If I lift it 2" wouldn`t the ball joint angle be the same no matter how it was lifted whether it be a spacer at the top and bottom or just one at the top?